Roscommon Famine emigrants

Re: Roscommon Famine emigrants

My GGfather Peter Higgins was born in New York in 1837-40 to John Higgins and unknown mother. I don't know where in New York and know nothing about John as to where in Ireland he came from. Peter eventually settled in Illinois and I am able to trace him from 1867 when he married Phoebe Flecher. Any enlightenment would be appreciated.